Table 3.
Laboratory difference between IgG4-TIN patients with glomerular lesions and those without glomerular lesions.
| IgG4-TIN with GL | IgG4-TIN without GL | P value | |
|---|---|---|---|
| Number of patients | 9 | 11 | |
| Age (years), mean ± SD | 73.8 ± 7.2 | 66.0 ± 7.7 | 0.036 |
| Serum creatinine (mg/dL) | 2.6 ± 2.4 | 1.4 ± 0.6 | 0.239 |
| Serum IgG (mg/dL) | 3865 ± 903 | 3162 ± 1251 | 0.16 |
| Serum IgG4 (mg/dL) | 909 ± 434 | 935 ± 413 | 0.909 |
| SerumC3 (mg/dL) | 43 ± 23 | 70 ± 27 | 0.068 |
| Low C4 | 7/9 | 5/11 | 0.197 |
| Low CH50 | 7/9 | 5/11 | 0.197 |
| IgG4 IHC (cells per hpf) | 43.0 ± 21.8 | 44.5 ± 39.4 | 0.493 |
| IgG4/IgG (%) | 50.4 ± 16.5 | 54.1 ± 20.8 | 0.518 |
| IF TBM IgG | 1/7 | 1/9 | >0.999 |
| IF TBM C3 | 4/7 | 3/9 | 0.615 |
| IF TBM C1q | 1/7 | 1/9 | >0.999 |
| EM TBM | 2/6 | 4/9 | >0.999 |
Note: Conversion factor for creatinine: mg/dL to μmol/L, ×88.4.
Abbreviations: EM: electron microscopy; GL: glomerular lesions; hpf: high-power field; IF: immunofluorescence; IHC: immunohistochemistry; TBM: tubular basement membranes; TIN: tubulointerstitial nephritis.